No Stanley the controller can control up to 50 amps , the battery or more properly the power supply must supply the current. This leads to the understanding that if you actualy get 50 amps to flow for a significant percentage of the time your wiring and connectors had better be correctly sized. From the pictures you are probably using closer to 1 amp than 50 amps
Also if I remember correctly you have had interferance problems with this project that may well get a lot worse with this addition due to wiring and layout related problems.
Another point some of the parameters for this controller will be set with the 50 amp current in mind. These settings may make this device hard to control with a load that uses significantly less current.
You also had questions about batterys. A device designed for 50 amps may well use .25 amps for internal control (.5% of load ) if used as intended. This will not affect battery life. If used to control a 1 amp motor it would indeed be a significant factor. HTH Terry